Process of producing laminated glass



- March 31, 1931.

G. B. wA'rKNs 1,799,075

4PROCESSO? PRoDUc'ING LAMINATED GLASS Filed July 25, 1928 4*" F; Wwf/@ TT; 5 Q

'4- V//Uw//W//i/N f 9%/ f7 @y z 'A ff- 5- W I l C ln/vaak@ Geo 17e B. wat/(m5 akker/uf vPatented Mar. 31, 1931 I v UNITE-D STATES 'PATENT OFFICE f `Geenen B. warms, or TOLEDO, on'Io, AssIeNon To LIBBnYfowENs-Fonn GLASS COMPANY, or reunio, omo, A conPoaATIoN on omo rnocnss or rnonucmcf LAMINATED GLASS Appia-ation ined July 23, 192s. seriai No. 294,856.

The present invention relates to laminated cordance-with dierent processes and by the glass and to the process of producing the use of various materials or ingredients. In same, most cases, however, it is desirable to seal the An important object of the invention 1s to laminated sheet whereby to protect the bond provide'an improved process wherein lamibetween lthe laminations to overcome the 55.

nated glass can be sealed without the usual tendency vof let-goes. Sheets of laminated steps of undercutting and introduction fof a glass even though properly joined at the time sealing material such as pitch. v of manufacture will develop let-goes if the A further object of the invention isto proedges of the sheet are not sealed. The elem vide a process wherein. the laminated sheet ments,etc.causingaseparation ofthe lamina- Gi is sealed by being subjected to the action of a tlons usually working from the edges inrelatively high boiling` point, low vapor preswardly of the sheet. VLet-goes is a term sure solvent or plasticizer without resorting used 1n .the art to designate portions Where to the customary method of mechanically rethe .lammations have become separated and movingaportion ofthe non-brittlemembrane obvlously if the laminations become sepa- C1 of the .laminated Sheet l .c rated the eiiiciency of the laminated sheet is A still further object of the invention is to greatly depreciated. In the past it has been provide such a process wherein laminated customary toseal laminated glass by formglass, consisting of two or more sheets of glass lng a channel around the laminated sheet and en and one or more non-brittle membranes interthen placmg a deposit of pitch or some '10 posed therebetween and united thereto, is Slmllfil Substance in the Channel aS Willbe sealed by treating the laminated sheet in a readlly understood. manner that the characteristics ofthe mar-v I Il accordance With thepresent invention ginal portions of the non-brittle membrane or 'lf/fo Sheets of glass 7 and 8 in lTig. 1 may be membranes are so changed that they will be Jolned to a non-brittle membrane by the aid made more plastic and will not tend to fail 0f il Sultable bonding liquid or the like 10. due to diiferential of expansion and contrac- The use 0f askin on the glass sheets can be tion between the glass and plastic membrane, resorted to as desired, as the present invention Other objects and advantages of theinven- 1s 1n no way limited to the lmanner of joining tion will become more apparent during the the laminations together or the ingredients C0 course of the following description when Used- The lamnations Shown in Flg. 1 may taken in connectionl with the vaccompanying be arranged in sandwich form which sanddrawings. Wlch 1s laced in a press designated in its In the drawings forming a part of this entirety y the numeral 1l where it is suba application and wherein like numerals are JeCted t0 the Combined action of heat and employed to designate like parts throughout pressure suiiicient to create an intimate bond the same, between the various laminations.'

Fig. 1 is a"fragmentary vertical section In Flg.v 3 is illustrated in section a sheet View showing the laminations before they are of glass 12 taken from the press 11. As illusxo joined. u trated the laminations are bonded together '53 ,Fig 2 represents diagrammatically a form throughout their entire areas and it will be I of press which maybe used. noted that the size of the non-brittle sheet Fi'g. 3 is a 'fragmentary vertical section of 9 1s identical with the size of the glass sheets a form of product. Y .so that their edges are all in alignment as Fig. 4 is a vertical sectional View showing lndicated at 13. f3 diagrammatically the treating of laminated Although the laminations are properly sheets to produce a seal, and joined upon removal from the press, provided Figs. 5 and 6 are fragmentary sections of of course the press hasbeen handled Apropertwo diiferenttypes of commercial product. 1y, aS filme gOeS O n the v`sheet 12 may develop l0 Laminated glass can be produced in ac'- let-goes. To protect the sheet, therefore, f-"J oint low va or ressure.

I have devised a new method of producing a seal. As shown the numeral 14 designates a suitable receptacle of sufficient capacity to contain a bath of liquid 15 in which may be submerged a plurality of laminated sheets 12. As it is customary to use a cellulose composition material as a non-brittle membrane of the sandwich the bath of material 15 preferred is triacetin,jhowever.there are other liquids and chemicals similar to triacetin, which have a relatively high boiling The sheets 12 may be suspended in the bath of triacetin or other'similar liquid by the clamps 16. By way o f example it is mentioned that the sheets 12 may be submerged in the triacetin bath for approximately thirty minutes. I have found that the.nonbrittle material will How and produce a seal designated by the numeral 17 in Figs. 5 and 6. No mechanical treatment is required to form the seal, the action of the triacetin being sufficient. It seems that the nonfbrittle sheet naturally flows over the ends of the glass sheets as illustrated. -The sheets are left in the solvent bath suiiiciently long to cause the proper amount of material. to iiow to adequately cover the. edges of the laminated sheet to produce an effective seal. l

When the laminated sheet is subjected to the action of triacetin or other relatively high boiling point, low vapor pressure solvent or plasticizer, tnltriacetin 'or equivalent liquid softens the Celluloid or" other nonbrittle membrane which causes a swelling or flowing thereof. At the same time the solvent replaces, so to speak, the camphor in the pyroxylin plastic around` the marginal por- `tions and in that respect produces a marginal border which is more plastic than the original pyroxylin plastic which will resist atmospheric elements better than nitro-cellulose colloidized with camphor, because camphor has a very high vapor pressure at normal temperatures and will gradually leave the plastic at the exposed edge causing a shrinkage with subsequent breaking of the bond causing development of let-goes, whereas a high boiling point, low vapor pressure solvent such as triacetin or 'the like will remain considerably longer in the plastic, thus materially prolonging the life of the laminated sheet. Furthermore, the triacetin of similar solvent is more tolerant to Water than camphor. Camphor is mentioned above because it is most' commonly used to colloidi'ze nitro-cellulose to produce commercial sheets of Celluloid or pyroxylin plastic sheets` By making the marginal portions of the non-brittle membrane more plastic, they will not tend to fail due to differential of expansion and contraction between the glass and plastic membrane. The length of time the laminated sheet is subjected to the solvent action is dependent, among other things,

upon the depth of penetration desired and temperature of the solvent. Under ordinary circumstances, the marginal treatment of the non-brittle membrane will not be great and probably not over one-quarter of an inch inwardly of the laminated sheet edges, al though, of course, the exact distance can be varied as is deemed advisable. It may also be desirable to place the laminated sheet and solvent under pressure during such treatment to accelerate the action thereof, although this is not essential. The solvent will penetrate substantially equally throughout.

I claim:

1. The process of sealing laminated glass having a layer of cellulose composition material, consisting in subjecting the laminated sheets tothe action of a cellulose composition material solvent bath sufficiently long to cause a flowing of the cellulose composition material sheet to vform a seal.

2. The process of sealing laminated glass having a layer of cellulose composition material, consisting in immersing the sheet into a bath of cellulose composition material solvent for a sufficient length of time to cause a flowing of the cellulose composition maet r ial sheet over the edges of the laminated s eet whereby to produce a seal.

3. The process of sealing laminated glass, consisting in immersing the sheet into a bath of triacetin for a sufiicient length of time to cause a iioWing of the non-brittle sheet over the edges of the laminated sheet whereby to produce a seal.

4. The process of scaling laminated glass comprising two sheets of glass and a sheet of non-brittle material, consisting in subjecting the .laminated sheet to the action of a relativelyvhigh boiling point, low vapor pressure solvent in a manner that the solvent will act upon the marginal portions of the non-brittle sheet for a relatively short distance inwardly of the edges thereof, the action of the solvent beingso controlled that the marginal por# tions of the non-brittle sheet affected will be made more plastic.

5. The process of sealing laminated glass comprising two sheets of glass and a sheet of non-brittle material, conslsting in subjecting the laminated sheet to the action of a relatively high boiling point, low vapor pressure solvent in a manner that the solvent will act upon the marginal portions of the nonbrittle sheet for a relatively short distance inwardly of the edges thereof, the-action of the solvent being so controlled that the marginal portions ofthe non-brittle sheet will be rendered more resistant to the action of the atmosphere.

6. The process of sealing laminated glass comprising vtwo sheets of glass and a sheet of non-brittle material, consisting in subjecting the laminated sheet to the action of a relatively high boiling point, low vapor pressure solvent in a manner that the solvent will 4act upon the marginal' portions of the nonbrittle sheet for a relatively short ydistance inwardly of the edges thereof, the solvent replacing, so to speak, the plasticizer in the non-brittle material so that the said marginal portions thereof will be made more plastic.

7. In the process of manufacturing laminated glass having a sheet of non-brittle'material interposed between. two sheets of glass, the steps of pressing the sheets of glass and the non-brittle material together, and thereafter subjecting the edge portions of the laminated sheet to the action of a relatively high boiling point', low vapor pressure solvent in a manner that the solvent will act upon the marginal portions of the n0n-brittle'.sheet fora relatively short distance inwardly of Vthe edges thereof to vmake the marginal portions more plastic.

8. In the process of manufacturing laminated glass havng'a layer of cellulose composition material interposed between two sheets of glass, the steps of pressing the sheets of glass and the cellulose composition material together, and thereafter immersing the sandwich thus formed in a bath consisting of a relatively high boiling point, low vapor pressure solvent for a suiiicient length of timeto cause the solvent to act upon the marginal portions of the cellulose composition material for a relacively'shrt distance inwardly of the edges thereof to make the marginal portions more plastic. l

Signed at Toledo, in the county of Lucas, and State of Ohio, this 20th day of'July,

GEORGE B. WATKINS. 

